Question

如何在WHERE中使用DISTINCT子句？例如：

SELECT * FROM table WHERE DISTINCT email; -- email is a column name

我想从具有不同电子邮件地址的表格中选择所有列。

Answer 1

如果您指的是其电子邮件唯一的所有列：

SELECT * FROM table WHERE email in
     (SELECT email FROM table GROUP BY email HAVING COUNT(email)=1);

Answer 2

可能是：

SELECT DISTINCT email,id FROM table where id='2';

Answer 3

select t1.*
from YourTable as t1
  inner join
    (select email
     from YourTable
     group by email
     having count(email) = 1 ) as t2
    on t1.email = t2.email

Answer 4

您可以使用HAVING子句。

SELECT * 
FROM tab_name
GROUP BY email_id
HAVING COUNT(*) = 1;

Answer 5

您可以使用ROW_NUMBER（）。您也可以指定条件。（例如，以下查询中的Name LIKE'MyName%）

SELECT  *
FROM    (SELECT ID, Name, Email,
            ROW_NUMBER() OVER (PARTITION BY Email ORDER BY ID) AS RowNumber
     FROM   MyTable
     WHERE  Name LIKE 'MyName%') AS a
WHERE   a.RowNumber = 1

Answer 6

一个简单的查询就可以了：

SELECT * 
FROM table 
GROUP BY email 
HAVING COUNT(*) = 1;

Answer 7

不会这样做：

 SELECT email FROM table1 t1 
          where UNIQUE(SELECT * FROM table1 t2);

Answer 8

简单查询，此查询从表中选择电子邮件唯一的所有记录：

select distinct email,* from table_name

Answer 9

如果表中有唯一的列（例如tableid），请尝试此操作。

SELECT EMAIL FROM TABLE WHERE TABLEID IN 
(SELECT MAX(TABLEID), EMAIL FROM TABLE GROUP BY EMAIL)

Answer 10

尝试：

SELECT * FROM table GROUP BY email

这将返回所有行，并在第一个ID出现时使用唯一的电子邮件（如果可以的话）
我认为这是您一直在寻找的东西，因为我有一个相同的问题，但是这些答案都不对我有用。

Answer 11

SELECT DISTINCT dbo.Table.Email，dbo.Table.FirstName dbo.Table.LastName，dbo.Table.DateOfBirth（etc）from dbo.Table.Contacts 电子邮件='name @ email';

Answer 12

查询：

Select *, (Select distinct email) from Table1

带有WHERE的DISTINCT子句

12 个答案: